Which orchids require the low level of light?

[alessandro2011]

And other questions of this subject, during the winter rest:
- the orchids need a lower level of light respect the active period?
- the deciduous variety need a lower level of light respect the active period? Given that the leaves fall, so this should reduce even the chlorophyll activity on the remain leaves?
Or, at least, if don't exist reference about that, who use a greenhouse and have a lux meter who might indicate the amount of light that gives for each species during the winter?

On this way, should be possible find out the minimum necessary to keep them healthy.

[King_of_orchid_growing:)]

First of all, I want to tell you something you may not know...

When a plant goes dormant it doesn't necessarily mean it goes deciduous. A plant can go dormant without going deciduous.

A plant can be fully deciduous, where all the leaves fall off.

Or...

Plants can also be considered semi-deciduous, where not all the leaves on the plant drop. Some leaves are still attached to the plant

It is not necessary to decrease the amount of light a deciduous orchid receives when it goes dormant and deciduous. If you're asking in regards to an epiphytical deciduous or semi-deciduous orchid, I highly discourage decreasing the amount of light it gets when the plant either becomes fully or semi-deciduous.

As far as low light level orchids that are readily available for hobbyists are concerned, whether they are evergreen, fully deciduous, or semi-deciduous, they are plentiful. Some are:

Phalaenopsis
Doritis
Kingidium
Masdevallia
Dracula
Pleurothallis
Acronia
Pescatorea
Kefersteinia
Cochleanthes
Warczewiczella
Bulbophyllum
Hapalochilus
Cirrhopetalum
Pholidota

If you're asking about terrestrial orchids, these are not the most readily available plants in the hobby and not the most widely grown. Although some of the Jewel Orchids come to mind if you're talking about orchids with a low light requirement.

Anoetochilus
Dossinia
Goodyera
Ludisia
Macodes

[alessandro2011]

How minimum ammount of lux are required from each variety of the above list of orchids?

[King_of_orchid_growing:)]

Idk, you might want to check out Charles and Margaret Bakers' culture sheets.

Orchid Culture -- Charles and Margaret Baker

[alessandro2011]

Very interesting.

[Ray]

Originally Posted by alessandro2011

How minimum ammount of lux are required from each variety of the above list of orchids?

I don't think you're ever going to get a definitive answer, as besides inter-specific variation, the whole thing is a continuum.

You might get really good growth and blooming if a particular plant is grown at 2000 fc, but slower growth and less-frequent blooming at 1000.

It is when the energy consumption outpaces the energy production that the plant will die, and they do slow down if grown darker.

[nenella]

Originally Posted by Ray

I don't think you're ever going to get a definitive answer, as besides inter-specific variation, the whole thing is a continuum.....

....It is when the energy consumption outpaces the energy production that the plant will die, and they do slow down if grown darker.

Ray, thanks for the ultra clear answers (in my mind), and in 'laymans' terms, to Ale's question; particularly your last phrase!

...I'm thinking about haraella retrocalla here in particular..